|
|
Physical interactions of the splicing factor Prp45
Kratochvílová, Eliška ; Folk, Petr (advisor) ; Doubravská, Lenka (referee)
It is well known that chromatin posttranslational state, transcription and splicing influence each other. Nevertheless, the details of this coupling are not fully understood. In S. cerevisiae, it is possible to induce conditions, in which splicing is uncoupled from transcription. Such situation occurred in cells expressing a mutated splicing factor Prp45, whose human homolog has been proved to participate in transcription regulation and also in splicing reactions. Based on previously indicated interactions in high throughput two-hybrid screens, we have been looking for physical links between Prp45 and proteins involved in chromatin posttranslational modifications. Finding of such a link would provide insight into the relationships of gene expression processes. Using coimmunoprecipitation and affinity purification, we were unable to detect physical interactions between Prp45 and our candidate chromatin regulators. Alternative approaches are discussed. Using the precipitation techniques, we mapped the interaction of Prp46 with truncated variants of Prp45. This observation contributes to our knowledge of protein-protein interactions within the spliceosome.
|
|
|
The role of SNW/SKIP proteins in splicing
Hollá, Sandra ; Novotný, Marian (advisor) ; Kozáková, Eva (referee)
SNW proteins are essential nuclear factors whose name was derived from the conserved motif SNW. They can be found with various representatives across the eukaryotic empire. SNW proteins are involved in regulating many cellular processes - for example regulation of gene expression and cell cycle. By far the most information about the function of human homologue provides SKIP/NCoA-62, which was found in a number of signaling pathways. Yet it is not fully understood the function of SNW proteins. In this work, I would like to focus on the role of SNW proteins in pre-mRNA splicing, particularly in the yeast Saccharomyces cerevisiae, where most results were acquired. Key words: SNW protein, Prp45, splicing pre-mRNA, SKIP/NCoA-62, Prp22
|
|
|
Splicing of atypical introns in S. cerevisiae
Cit, Zdeněk ; Půta, František (advisor) ; Pichová, Alena (referee)
Pre-mRNA splicing is a vital process of gene expression important for all eukaryotic organisms. For the proper function of this very complex and dynamic event the presence of few specialized RNA and many proteins that hold a variety of tasks is necessary, not only inside the splicing complex itself, but also beyond this complex. The Prp45 is one of the proteins involved in pre-mRNA splicing in yeast Saccharomyces cerevisiae. Its human homologue, SNW1/SKIP, is involved in splicing but also in other crucial cell processes. The Prp45 protein was reliably reported only to participate in the second transesterification reaction of splicing. But there are also data suggesting its possible involvement in the first transesterification reaction. This work provides further evidences linking protein Prp45 with the first splicing reaction, obtained by the research of cells carrying the mutant allele prp45(1-169). Cells carrying this allele show dropped splicing and accumulation of pre-mRNAs. This thesis therefore also investigated the possible influence of Prp45 protein on the RNA export from the nucleus to the cytoplasm. But no connection between this protein and RNA transport was discovered. Keywords pre-mRNA splicing; Saccharomyces cerevisiae; Prp45; Mer1; Mud2; Prp22; Rrp6; AMA1; SNW1/SKIP
|
|
|
The role of SNW/SKIP proteins in splicing
Hollá, Sandra ; Novotný, Marian (advisor) ; Kozáková, Eva (referee)
SNW proteins are essential nuclear factors whose name was derived from the conserved motif SNW. They can be found with various representatives across the eukaryotic empire. SNW proteins are involved in regulating many cellular processes - for example regulation of gene expression and cell cycle. By far the most information about the function of human homologue provides SKIP/NCoA-62, which was found in a number of signaling pathways. Yet it is not fully understood the function of SNW proteins. In this work, I would like to focus on the role of SNW proteins in pre-mRNA splicing, particularly in the yeast Saccharomyces cerevisiae, where most results were acquired. Key words: SNW protein, Prp45, splicing pre-mRNA, SKIP/NCoA-62, Prp22
|
|
|
The interaction of Prp22 and Prp45 proteins in budding yeast spliceosome
Senohrábková, Lenka ; Půta, František (advisor) ; Malcová, Ivana (referee)
Protein Prp22 is a DEAH box RNA helicase, which plays two distinct roles in pre-mRNA splicing: it participates in second transesterification step (ATP independent function) and it releases mature mRNA from the spliceosome (ATP dependent function). Prp45p, yeast ortholog of the human transcription co-regulator SNW/SKIP, is an essential splicing factor, it is included in spliceosome throughout the splicing reaction. Mutant prp45(1-169) genetically interacts with some alleles of NTC complex and second step splicing factors, one of them is also gene PRP22. Here we present, that mutants prp22(-158T) and prp22(-327A), which are synthetically lethal with prp45(1-169), express lower amount of Prp22p due to the mutation in upstream regulation region. Mutants prp22(-158T), prp22(300PPI) and prp22(-327A) affect splicing of pre-mRNA with mutation in 5'ss with respect to sequence of the second exon. N-terminal mutants prp22(∆301) and prp22(∆350) are synthetically lethal with prp45(1-169). Synthetic lethality is possibly caused by lower efficiency of Prp22 recruitment to the spliceosomes, which is no more viable for cells.
|
|
|
Physical interactions of the splicing factor Prp45
Kratochvílová, Eliška ; Folk, Petr (advisor) ; Doubravská, Lenka (referee)
It is well known that chromatin posttranslational state, transcription and splicing influence each other. Nevertheless, the details of this coupling are not fully understood. In S. cerevisiae, it is possible to induce conditions, in which splicing is uncoupled from transcription. Such situation occurred in cells expressing a mutated splicing factor Prp45, whose human homolog has been proved to participate in transcription regulation and also in splicing reactions. Based on previously indicated interactions in high throughput two-hybrid screens, we have been looking for physical links between Prp45 and proteins involved in chromatin posttranslational modifications. Finding of such a link would provide insight into the relationships of gene expression processes. Using coimmunoprecipitation and affinity purification, we were unable to detect physical interactions between Prp45 and our candidate chromatin regulators. Alternative approaches are discussed. Using the precipitation techniques, we mapped the interaction of Prp46 with truncated variants of Prp45. This observation contributes to our knowledge of protein-protein interactions within the spliceosome.
|
guest ::
